SYSTEMS AND METHOD FOR FORMING BIPLANAR OSTEOTOMIES
Apparatus and methods are disclosed for determining and placing a first bony segment in relation with a second bony segment, both segments belonging to the same bone, including cutting said bone partially, to separate it into the first and second bony segment. The two bony segments are linked together by a bony hinge and placing the two boney segments in relation to each other may include distracting both bony segments around said hinge. The hinge may be configured to allow distraction of both bony segments around a single degree of freedom of the hinge and accommodate corrections in two substantially orthogonal planes.
This application claims benefit to Provisional Patent Application No. 62/967,252; filed Jan. 29, 2020; and Provisional Patent Application No. 63/054,561; filed Jul. 21, 2020; and Provisional Patent Application No. 63/108,238; filed Oct. 30, 2020, all titled “SYSTEMS AND METHOD FOR FORMING BIPLANAR OSTEOTOMIES”; herein incorporated by reference in their entirety.
This application incorporates by reference commonly owned Patent Application PCT/US20/019094 filed Feb. 20, 2020; and Provisional Patent Application No. 62/808129 file Feb. 20, 2019, both titled “SYSTEM AND METHOD FOR HIGH TIBIAL OSTEOTOMY”.
FIELD OF THE INVENTIONThis invention is related to surgical apparatus and methods in general, and more particularly to apparatus and methods for forming a biplanar osteotomy, to realign bones.
BACKGROUNDOsteotomies of the lower limbs are an important technique for modifying the loadbearing geometry of the knee. For example a tibial osteotomy may treat knee osteoarthritis by adjusting the geometry of the knee joint to transfer weight bearing loads from arthritic portions of the joint to relatively unaffected portions of the joint. As another example tibial or femoral osteotomies may address abnormal knee geometries, e.g., due to birth defect, injury, etc. Most lower-limb osteotomies are designed to adjust the manner in which the load is transferred across the knee joint. One method of adjusting the orientation of the tibia, is an open wedge technique, represented in
For a detailed description of example embodiments, reference will now be made to the accompanying drawings in which:
1D shows a femur osteotomy open and closed wedge, in the coronal plane only, for reference purposes;
Various terms are used to refer to particular system components. Different companies may refer to a component by different names—this document does not intend to distinguish between components that differ in name but not function. In the following discussion and in the claims, the terms “including” and “comprising” are used an open-ended fashion, and thus should be interpreted to mean “including, but not limited to . . . .” Also, the term “couple” or “couples” is intended to mean either an indirect or direct connection. Thus, if a first device couples to a second device, that connection may be through a direct connection or through an indirect connection via other devices and connections.
Generally, this disclosure is directed to a realignment of a bone, which may include forming a wedge in the bone that may be an open wedge, tibial osteotomy of the knee, and is intended to provide a cut having a predetermined or calculated apex. This predetermined apex or boundary defines an axis of rotation while opening the osteotomy, the axis determined to incorporate both coronal and sagittal corrections. While existing methods include forming an osteotomy 90 accounting for a single plane correction only, as discussed with reference to
Various embodiments are directed to a surgical method of attachment of a first bony segment in relation with a second bony segment, both segments belonging to a same bone. The method may include cutting the bone partially, to separate it in two bony segments linked together by a bony hinge and distracting or rotating both bony segments around the bony hinge, wherein the bony hinge is configured to rotate both bony segments around a single degree of freedom of the bony hinge and accommodate two substantially orthogonal correction planes. Twisting the bony hinge as shown in
An alternative surgical method is disclosed for attaching a first bony segment in relation with a second bony segment, both segments belonging to a same bone. The method includes cutting partially into the bone, cutting being implemented until obtaining a partial cut, which separates partially the bone into two bony segments linked together by a bony hinge, the bony hinge defining a hinge axis that is oriented at a non-zero angle relative to a sagittal plane through the bone. The method also includes rotating the first bony segment with respect to the second bony segment about said bony hinge about a single degree of freedom until obtaining a desired three-dimensional alignment of the two bony segments, including a biplanar correction as defined herein, and reaching a position in which facing sides of said bony segments are separated from each other by a predetermined opening angle. In some embodiments, the method may also include determining a hinge rotation angle relative to the sagittal plane using a targeted varus correction angle input and a targeted anterior-posterior slope correction angle input, thus defining a hinge axis angle that provides rotation of the first bony segment with respect to the second bony segment around the single degree of freedom. In some embodiments, the method may include determining the hinge rotation angle (θ) using physical charts. In some embodiments, the method may include determining the hinge rotation angle (θ) using a computer program. In some embodiments, the method may include drilling a hole and thus creating a boney hinge axis. In some embodiments, the method may include drilling the hole using preplanning navigation. In some embodiments, the hole may be drilled using a computer piloted robot whose working head is able to be moved according to at least three degrees of freedom. In some embodiments, the method may include cutting the bone, implemented by using a computer piloted robot whose working head is able to be moved according to at least three degrees of freedom, the working head supporting a cutting tool. In some embodiments, the method may include using a cutting guide to guide the orientation of the cutting tool.
A further method is disclosed of controlling a computer piloted robot having a working head that moveable according to at least three degrees of freedom, in order to implement a surgical method of attachment of a first bony segment in relation with a second bony segment, both segments belonging to a same bone. When a cutting tool is coupled to the working head, this method includes causing the cutting tool to cut partially the bone until obtaining a partial cut, which separates partially the bone in two bony segments linked together by a bony hinge, the bony hinge defining a single hinge axis. The method also includes rotating the two bony segments about a single degree of freedom to reorient the first bony segment relative to the second bony segment to a desired orientation including non-zero corrections in two substantially orthogonal planes. In some methods, the two substantially orthogonal planes may include the coronal and sagittal correction. In some methods the computer controlled robot may be in communication with a computer, the computer configured to preoperatively or intra-operatively determine the position and direction of the partial cut, calculating its depth, calculating an opening angle and the relative position of the first bony segment with respect to said second bony segment necessary to obtain the final desired alignment of the two bony segments, the final desired alignment including a biplanar correction.
A non-transitory computer-readable medium is also disclosed that stores a program that, when executed by a processor is configured to cause the processor to receive a value indicative of a first correction angle of a bone and receive a value indicative of a second correction angle of a bone, substantially orthogonal to the first correction angle. This processor is configured to determine a value indicative of a modified bony hinge axis angle including both the first and second correction angle. This processor may also be configured to determine a value indicative of a final wedge opening angle of a first bony segment of the bone relative to a second bony segment of the bone accommodating both the first and second correction angle. In some embodiments the processor may be communicably coupled to a computer piloted robot having a working head that is moveable according to at least three degrees of freedom, and wherein the program, when executed by the processor is configured to cause the computer piloted robot to orient the working head to the determined modified bony hinge angle, determined by the processor. In some embodiments, the computer piloted robot may be in communication with navigation sensors, configured to aid in orienting the working head at the determined modified bony hinge angle. In some embodiments when a cutting tool is coupled to the working head, the processor may be configured to cause the computer piloted robot to cut partially into the bone with the cutting tool until obtaining a partial cut which separates partially the bone into the two bony segments linked together by a bony hinge, the bony hinge oriented at the modified bony hinge axis. In some embodiments when a drilling tool is coupled to the working head, the processor may be configured to cause the computer piloted robot to drill into the bone along the modified bony hinge axis. In some embodiments when a wedge-opening tool is coupled to the working head, the processor may be configured to cause the computer piloted robot to distract the two bony segments to the final wedge opening angle by rotating the first bony segment relative to the second bony segment about a single degree of freedom. In some embodiments when a cutting guide is coupled to the working head, the processor may be configured to cause the computer piloted robot to orient the cutting guide in a desired orientation according to the determined modified boney hinge axis.
In addition, an example surgical method of attachment of a first bony segment in relation with a second bony segment, both segments belonging to a same bone, is disclosed herein including the step of: determining a modified hinge axis angle of a boney hinge that provides a single degree of freedom rotation of the first bony segment relative to the second bony segment, the modified hinge axis angle accounting for a final desired alignment of the two bony segments including two substantially orthogonal plane corrections. An aimer assembly is then placed around the bone. The method may include orienting a guide tube of the aimer assembly in a first orientation and then moving the guide tube along an aimer arm of the aimer assembly to orient an axis of guide tube along the determined modified hinge axis angle. A drill may then be inserted through the guide tube to form a hole through the bone, the axis of the hole defining the modified hinge axis of the bony hinge. In some example methods, moving the guide tube includes sliding the guide tube along the aimer arm. Moving the guide tube may include moving the guide tube up to a target numerical value indicated on the aimer assembly correlating to the modified hinge axis angle. Placing the aimer assembly may include first placing a posterior retractor around a posterior portion of the bone and coupling the aimer arm within a slot of the posterior retractor to place the aimer arm around a medial and anterior portion of the bone. Orienting the guide tube in a first orientation may include manipulating a handle extending from the posterior retractor. The first orientation may be defined as an orientation accounting for only one of the two substantially orthogonal plane corrections. The example method may also include removing the drill from the guide tube; and inserting a hinge pin through the guide tube. The example method may include inserting the hinge pin through the drilled hole to positively-engage a portion of a posterior retractor. The example method may include removing the aimer assembly from the posterior retractor, leaving the hinge pin within the hole and coupled to the posterior retractor; and coupling an osteotomy cutting guide to the posterior retractor and hinge pin.
An example embodiments of an aimer assembly is disclosed herein for forming a hole through a bone at a predetermined modified hinge axis angle. The example assembly includes an aimer arm that links to a retractor and extends around an outer portion of the bone. The assembly also includes a guide tube coupled to the aimer arm configured to move along the aimer arm and thereby around the bone and alter the guide tube orientation relative to the bone. The guide tube is configured to receive a means of forming a bone hole therethrough. The guide tube and aimer arm each include indicating markers that cooperate with each other to indicate a value correlating to the guide tube orientation relative to the modified hinge axis angle. In some example embodiments, the guide tube is slidingly coupled to the aimer arm. In some example embodiments, the guide tube is also configured to receive a hinge pin therethough, to place the hinge pin through the bone. In some embodiments, the guide tube aims the hinge pin towards an engagement mechanism of the retractor. The indicating markers may include numerical values on the aimer arm that correlate to the modified hinge axis angle. The numerical values may provide for a modified hinge axis angle up to 31 degrees relative to a reference angle. The reference angle may define an angle accounting for a single correction plane to the bone, the modified hinge angle accounting for a biplanar correction. The guide tube and aimer arm are configured to disconnect from the hinge pin and retractor, leaving the hinge pin and retractor coupled with each other and the hinge pin remaining through the bone hole.
Example embodiments of a laminar spreader are also disclosed herein, for separating two opposing sides on an osteotomy. An example laminar spreader may include a base having a distal end tapered to slip between the two sides of the osteotomy. The laminar spreader may also include a lifter having a proximal free end and pivotally coupled to the base adjacent the base distal end, that rotate relative to the base defining a cavity between the base and lifter. The laminar spreader may also include a wedge construct operably coupled to the base and configured to axially move a wedge of the wedge construct along the cavity to rotate the lifter and define an angle of separation of the two sides of the osteotomy. In some example embodiments, the wedge construct includes a lead screw orientated parallel to a base longitudinal axis and operable coupled to the wedge. Rotation of the lead screw axially moves the wedge along the cavity. The wedge may engage the lifter at a discrete portion of a top surface of the wedge. The wedge top surface may be disposed within the cavity and may be spaced away from the lifter. The wedge may engage the lifter at a location configured to indicate a separation value of the two sides of the osteotomy.
An example method of attaching a first bony segment in relation to a second bony segment, both segments belonging to a same bone is disclosed, including cutting partially into the bone, the cutting being implemented until obtaining a partial cut, which separates partially said bone in two bony segments linked together by a bony hinge. The bony hinge may define a modified hinge axis angle that is oriented to account for a biplanar correction. The method also includes rotating the first bony segment with respect to said second bony segment around the bony hinge about a single degree of freedom until obtaining a desired three-dimensional alignment of the two bony segments, in which facing sides of said bony segments are separated from each other by a predetermined opening angle. The method also includes fixing the desired three dimension alignment of the two boney segments with a bone plate, the bone plate including a bone engaging surface and holes therethrough, the engaging surface contour and the at least one of the holes' orientation at least partially configured to account for the modified hinge axis angle. In some embodiments, the bone plate bone-engaging surface is contoured to match a contour of the preferred location of the first and second segment of the bone that is approximately parallel with the modified hinge axis. In some embodiments, the bone plate bone-engaging surface is contoured to position the plate at a location approximately facing the modified hinge axis. In some example embodiments, at least one of the holes through the plate defines a complex aperture including two overlapping threaded holes that are oriented at an angle to each other. The angle between the two overlapping threaded holes may be at least partially defined by the modified hinge axis. For a larger predetermined modified hinge axis relative to a hinge axis for a single correction plane only, the angle difference between the two overlapping holes axes is reduced. In some example methods, the bone is a bone of the knee and the method may also include forming a tunnel through the bone for reconstructing an ACL and wherein the two overlapping threaded holes are configured to place at least one fixation member therethrough in a direction that avoids the tunnel through the bone. In some example methods, the holes through the plate defines an inferior plurality of holes configured to orient a fixation member extending therethough at a first angle and a superior plurality of holes configured to orient a fixation member extending therethough at a different angle to the first angle, defining an offset angle configured to account for torsion along the bone that results from the modified hinge axis. The larger the modified hinge axis relative to a hinge axis for a single correction plane only, the larger the offset angle.
Another example plate is disclosed herein for fixing a first boney segment relative to a second segment of the same bone, after the two segments have been distracted around a bony hinge. The bony hinge may be configured to rotate about a single degree of freedom and may be oriented at a modified hinge angle axis to obtain a desired three-dimensional alignment of the two bony segments accounting for two orthogonal correction planes, in which facing sides of said bony segments are separated from each other by a predetermined opening angle. The plate may include a bone-engaging surface configured to match a surface of the plate at a preferred location accounting for the modified hinge angle axis. In some examples, the bone is a bone of the knee and a tunnel may be formed for reconstructing or repairing an ACL. The plate may include an aperture through a superior portion of the plate configured to aim a fixation member to accommodate a concomitant ACL repair or reconstruction. The fixation member may extend through the aperture and adjacent to, but not intersect the tunnel formed therethrough. In some example embodiments, the aperture defines a complex aperture including two overlapping threaded holes that are oriented at an angle to each other and wherein the angle is at least partially defined by the modified hinge axis angle. For a larger predetermined hinge axis angle relative to a hinge axis for a single correction plane only, the smaller the angle is between the two overlapping holes. The two overlapping threaded holes are configured to place at least one fixation member therethrough in a direction that avoids the tunnel for reconstructing the ACL. In some example embodiments, the plate bone-engaging surface is contoured to match surface contours of the bone at the preferred location, which is traverse the distraction and approximately faces the modified hinge axis angle. The plate may include a plurality of apertures through the plate defining an inferior plurality of apertures configured to orient a fixation member extending therethough at a first angle and a superior plurality of apertures to orient a fixation member extending therethough at an offset angle to the first angle, configured to account for torsion along the bone due to the modified hinge axis angle, and wherein the larger the modified hinge axis angle relative to a hinge axis angle for a single correction plane only, the larger the offset angle.
In addition a bone plate flexing system for compression of a bony lateral hinge of an open wedge osteotomy is disclosed, the flexing system for use with a bone plate and fasteners. The bone plate defines a plurality of threaded holes for receiving a plurality of the fasteners therethrough in engagement with the threaded holes. The bone plate includes a bone contacting first surface, an opposing second outer surface, and a thickness extending in a dimension between said the first and second surfaces. The system includes a first shaft having a handle end and a threaded end for threadingly engaging with a first threaded hole of the plurality of the threaded holes. The system also includes a second shaft having a handle end and a threaded end for threadingly engaging with a second threaded hole of the plurality of the threaded holes. The first and second shafts each define a longitudinal axis. The system also includes an apparatus having a distal end configured to engage both shaft handle ends. The apparatus also includes actuation means for moving the first and second shaft handle ends relative to each other while engaged with the bone plate, and thereby elastically flexing the bone plate.
In some example embodiments, the apparatus includes a means of maintaining the bone plate in an elastically flexed configuration. The first and second shafts may both define drill guides. The first and second shaft threaded ends may define a length longer than the plate thickness such that the threaded ends extend beyond the first surface of the plate and form a local standoff between the first surface and bone. The first and second shaft ends may be independently engageable with the bone plate and may by engaged and disengaged by hand. The first and second shaft ends may both engage holes of the bone plate that are disposed either side of a third hole of the plurality of holes. The first and second shaft ends may both engage holes of the bone plate that are disposed at opposing ends of the plate, such as the inferior end and superior end. The first and second shaft ends may both engage holes of the bone plate that are one each side of the osteotomy distraction.
A method of elastically flexing a bone plate and thereby compressing a bony hinge of an open wedge osteotomy is also disclosed herein. The bone plate stabilizes the open wedge osteotomy and includes a superior portion for fixing with a superior side of the osteotomy and an inferior portion for fixing with an inferior side of the osteotomy. The method includes placing a bone plate adjacent an osteotomy of a bone, the bone plate having a first plurality of threaded holes disposed through the plate superior portion and a second plurality of threaded holes disposed though the plate inferior portion. The superior portion of the plate is fixed to the bone. A first elongate body is engaged with one of the holes of the first plurality of holes, and a second elongate body is engaged with one of the second plurality of holes. A plate-flexing tool is then engaged with the first and second elongate bodies. Using the plate-flexing tool, a force is applied via the first and second elongate bodies, to elastically-flex the plate along the plate longitudinal axis. While applying the force, the bone plate is further fixed to the bone, at a location spaced between the first and second elongate bodies, and thereby compressing the bony hinge. In some example methods, applying the force to elastically-flex the plate moves the inferior portion of the plate further away from the bone. The method may include releasing the plate-flexing tool from the first and second elongate bodies after fixing the portion of the bone plate to bone at the location spaced between the first and second bodies, and thereby relaxing the inferior portion of the plate towards the bone.
DETAILED DESCRIPTIONThe following discussion is directed to various embodiments of the invention. Although one or more of these embodiments may be preferred, the embodiments disclosed should not be interpreted, or otherwise used, as limiting the scope of the disclosure, including the claims. In addition, one skilled in the art will understand that the following description has broad application, and the discussion of any embodiment is meant only to be exemplary of that embodiment, and not intended to intimate that the scope of the disclosure, including the claims, is limited to that embodiment.
The disclosure may generally include improved methods and systems to determine, form and fixate a bone alignment adjustment that includes an osteotomy and accommodates a bone alignment with correction in two substantially orthogonal planes. This disclosure may include improved systems and methods of ACL repair or reconstruction that includes a concomitant bone alignment adjustment. These methods and systems may determine a modified open or closed wedge angle and boney hinge axis that accommodates a targeted bone alignment including two substantially orthogonal planes. These two substantially orthogonal planes may be the sagittal and coronal planes of the body. This disclosure may also include methods including calculating or determining an improved hinge-opening angle and hinge axis to accommodate a targeted bone alignment around two substantially orthogonal planes. This hinge-opening angle and hinge axis are configured to rotate the osteotomy about a single degree of freedom only, and thereby require no twisting of the boney hinge to accommodate the biplanar alignment. This disclosure also includes systems for forming and maintaining this improved osteotomy cut angle and/hinge line and hinge opening angle, accommodating for changing forces and torsions on the bone. The osteotomy may be part of a high tibial osteotomy, or a lower (or distal) femur osteotomy. The osteotomy may be part of shoulder-elbow-wrist (SEW) realignment. The osteotomy may be part of a procedure including an open-wedge osteotomy or closed wedge osteotomy. In a closed wedge osteotomy, a wedge of bone is removed and the two segments rotated towards each other. This disclosure may therefore also include determining parameters associated with the size, angle and location of the wedge of bone to be removed, such that upon removal, rotation of the two segments rotates them around a single degree of freedom and accommodates a biplanar correction.
The desired correction angle including the two substantially orthogonal planes may be determined during a pre-operative planning stage of the procedure. For example using a series of several preoperative medical images and data (x-rays echography, MRIs or CAT scans for example), the surgeon knows for example the pathologic angle HKA (Hip-Knee-Ankle) or alternatively SEW (Shoulder, Elbow, Wrist) of his patient. For example, represented in
The computer may also address combined surgeries such as Anterior Cruciate Ligament (ACL) reconstruction with the High Tibial Osteotomies (HTO). In this example, the ACL reconstruction tunnels and osteotomy cut with plating screws could inadvertently intersect, creating negative surgical outcomes. With 3D computer navigation, this issue could be eliminated. Alternatively, rather than using a computer, on the basis of these medical images a chart or look-up table may be referenced directly by the surgeon to determine at least one of the position, the orientation and the depth of the future partial cut, the angle of the hinge axis relative to the sagittal plane and the relative three dimensional positions of the first bony segment with respect to the second bony segment. In other embodiments, a mechanical computer may be used, wherein two angles based on the medical images may be input into a mechanical computer construct that mechanically resolves the rotation and wedge angle via cams and linkages.
For example for desired Varus and AP slope corrections angles, using for example the two images in
Similar calculations may be made for other bones, using similar references. For example, the modified axis may be rotated about a longitudinal axis of a bone and with reference to any plane along the bone that is appropriate, anatomically. For example, the rotation angle θ could be calculated relative to either a sagittal or coronal plane through the bone.
In addition, a new distraction angle γ′ may be determined, and is a resultant angle taking into account the two substantially orthogonal angles; the Varus correction angle 400, and the AP slope correction angle 410. This new distraction angle γ′ or single combined “Total Angle” in combination with the modified hinge axis angle is configured to orient the first bony segment relative to the second boney segment, with rotation about a single degree of freedom, (without twisting of the two bony segments relative to each other) accounting for at least two substantially orthogonal creation planes.
The equation that may determine the resultant wedge angle γ′ with known AP and Varus look as follows.
An example look up table, using the above equations is shown below. V/V represents the Varus correction angle 400, A/P represents the AP slope correction angle 410. “Total Angle” is the resultant Wedge opening (γ′), or described above. “Rotation Angle” in the chart below is the “Hinge 4” per the equation above, and is the modification in angular degrees)(° to the hinge line axis, indicated as 0 on
AP slope correction may include increase or decrease the AP Slope for the tibial plateau. The osteotomy will open opposite the boney hinge location. If the hinge is rotated anteriorly (or clockwise) as shown in
An example aimer assembly 800 is disclosed in at least
In alternative systems and methods, a hinge pin 600 may be eliminated and a cutting guide 610 may be configured to place the cutting tool 620 at a desired orientation to form a cut that is adjusted and oriented at an angle to the sagittal plane according a determined modified angle. The terminal end of the cut therefore defines the modified hinge axis 450 or boundary that defines a modified hinge axis, the modified angle (θ) that is non-parallel to the sagittal plane. Alternatively, an aimer assembly 800 may be avoided and a drill bit may be coupled to a working end of a robot operable to orient the drill bit at the desired orientation and location, to orient the hinge pin 600 in the determined orientation and place it into the bone. Alternatively, an aimer assembly 800 may be avoided and a cutting tool may be coupled to a working end of a robot operable to orient the cutting tool at the desired orientation and location, to orient the osteotomy 600 in the determined orientation to form an osteotomy partially through the bone that terminates at a boundary that aligns with the predetermined modified hinge axis.
An alternative system and method may include forming a patient specific cutting guide and/or hinge pin orientation construct. This may be used to place a hinge pin through the bone 80 and/or corresponding cutting plane, accounting for the two substantially orthogonal correction planes. Similar to the previous example disclosed, this example system and method may include determining the modified hinge axis angle and location or a cutting plane orientation and location. This example system and method may include determining a cutting guide surface morphology that conforms to external surfaces contours of the tibia. The guide surface contours may be configured to place the guide in the target location and orientation that forms the predetermined osteotomy. More specifically the guide contours may position the guide and may orient a hinge pin and/or cutting saw 620 through the tibia at the determined location and orientation that realigns the bone with a rotation about a single degree of freedom and accommodates a biplanar correction. The guide morphology may be determined using images (CT or X-ray for example), and 3D images. Determining the 3D surface morphology may include using a computer program. A mechanical guide may be formed or modified according the determined morphology, specific to the patient, based on these images received. For example an inner surface of the guide may be formed or modified to have an inner surface morphology configured to engage and match a determined location of a medial side of the tibial external surface, specific to the patient. Matching is preferably configured to place a saw 620 at the determined starting location and orientation to form the determined osteotomy trajectory. The guide 610 may also include a construct that aligns the hinge pin 600 at the determined angle. The hinge pin alignment construct may include a patient matched reference surface specifically configured to align the hinge pin through the tibia at the determined modified axis angle. The hinge pin patient matched reference surface may cooperate with a surface of the guide or with external surface of the patient bone.
The hinge pin 600 may locate the cut guide 610 in the target position and orientation to produce the preferable osteotomy plane angle relative to the modified hinge axis angle θ. The cutting guide 610 may connect to the posterior retractor 850. The hinge pin 600 also provides a barrier or border to the osteotomy, thereby limiting travel of a saw (such as tool 620) creating a high precision osteotomy cut. Cutting guide 610 and pin 600 may then be removed and an anterior cut guide 900 placed adjacent the tibia 80 to orient a transverse cut to relieve the patella tendon. An example anterior cut guide 900 is shown with a lip that may fit between the two boney segments, formed by the osteotomy. Anterior cut guides are disclosed in at least commonly owned patent application No. 62/808,129 filed Feb. 20, 2019, titled “SYSTEM AND METHOD FOR HIGH TIBIAL OSTEOTOMY”; herein incorporated by reference in its entirety. This anterior cut allows the osteotomy opening to occur.
During preplanning, the surgeon may use a series of charts provided, examples of which have been disclosed herein. For example, for a determined Varus correction (degrees) and a determined AP slope Correction (degrees) a modified hinge axis angle orientation (degrees) may be determined and the aimer 800 may orient a guide tube and thereby the hinge pin 600 at this determined axis angle. In addition, with the same two input corrections, a chart may also provide an overall opening angle (Hinge ). Alternatively, a wedge opening distance (in mm for example) may be provided in lieu of or in addition to an opening angle γ. In alternative embodiments a computer program or app may convert the two input correction angles and provide the surgeon with the modified hinge angle axis and wedge opening dimension.
Seen in
For example, shown in
An alternate embodiment is illustrated in
The disclosure now turns to fixation plate embodiments configured to provide fixation and optional compression to a bony hinge that may accommodate a biplanar alignment that avoids twisting of the boney hinge, as described herein. Generally, the inventors have found that modifications to the osteotomy orientation and axis of rotation leads to changes in torsional forces along the bone and torques on the bony hinge. Therefore a plurality of improved plate embodiments to account for these changes are disclosed. Firstly plate fixation may preferably be disposed directly opposite the modified hinge axis, where anatomy allows. In addition should a concomitant ACL reconstruction procedure add a tunnel to the tibia, the plate may include apertures than direct fixation members such as locking or compression screws around or away from this tunnel. The configuration of these apertures may depend on the modified hinge axis and thereby plate location. A series of plates is therefore envisioned depending on the modified hinge axis. Some plate embodiments may include contours that match anatomy of the preferred location on the bone that may be directly opposite a series of hinge axis angles, given other anatomy considerations such as the MCL. This series of plates may also include apertures specifically configured to accommodate an ACL tunnel, given the preferred location of that plate. The plate may also include an offset axis between a proximal head and distal tail of the plate, to account for torsional forces on the tibia and local anatomy considerations.
Illustrated in
Complex aperture 1220 is preferably placed on a superior portion of plate 1200 and through a portion of the plate 1200 configured to be closest to an anterior side of the tibia. The anterior portion during ACL reconstructive surgery may have a tunnel formed through the tibia and a graft placed therealong. Depending on the tunnel location, the second axis orientation 1221b may preferably place a fixation screw in a location that will not interfere with an ACL reconstruction tunnel or meniscal root repair tunnel.
The disclosure now turns to a discussion of the changes in forces on the tibia 80 when the hinge axis angle is rotated.
Therefore a plurality of plates may be provided, not only to accommodate the left or right patient leg, or different tibia sizes but also to accommodate an adjusted placement of a plate to reduce torque on the bony hinge 81, for a modified hinge axis angle θ. For example, for a biplanar correction for a decreased A/P correction as shown in
A plurality of plates may be provided to accommodate a series of modified hinge axis angles. The plate may include a contour to match a preferred location based on the modified hinge axis angle. The plate may include a complex aperture as disclosed herein, the complex aperture having at least two axis orientations that may be different from each other. The two axes may be angularly offset by a value defined by the modified hinge axis angle or modified osteotomy orientation as disclosed herein. The two axes may be angularly offset to provide a plurality of placement angles of a fixation device while avoiding the ACL tunnel or MCL relative to that preferred location. For example, a first plate of the plurality of plates may include a first custom contoured shape that matches a first portion of the tibia outer surface and may also include a first complex aperture having a pair of axes angularly offset from each other to provide a means to avoid and ACL tunnel. The plurality of plates may also include a second plate including a second custom contoured shape that matches a second portion of the tibia outer surface, different than the first portion due to a modified hinge axis angle. The second plate may also include a second complex aperture having a pair of axes oriented at a second angular offset different than the first angular offset of the first plate, configured to provide a means to avoid and ACL tunnel.
In addition, plate inferior surface portion 1520 may be oriented at angle X to the longitudinal axis L1 of superior portion 1525. This allows for improved apposition with the bone surfaces in this medial location. In addition, inferior portion 1520 may define a longitudinal axis L3 extending through at least two central axes of holes 1210, L3 offset (W) from a longitudinal axis L2 of plate. This places the superior portion 1525 more medially on the tibia superior portion and more anteriorly on the tibia inferior side of the osteotomy, to center the inferior stem 1520 along the tibia and resist torsional moments on the tibia as a result of the modified hinge axis angle. A plate that accommodate a larger modified hinge axis angle, may have larger values of W and X relative to a plate that accommodates a smaller modified hinge axis angle.
The disclosure now turns to a system 1600 for adjusting and increasing compression to a lateral bony hinge of an HTO. This system may be applicable for both the more traditional single plane open-wedge high tibial osteotomy as well as the biplanar HTO as disclosed herein. Increased compression on the bony hinge 81 may improve the patient outcome in a variety of ways. It may facilitate faster bone healing during an HTO procedure; it may decrease a chance of non-union should the bony lateral hinge crack during the procedure; and it may allow for earlier weight bearing on the osteotomy as it preloads the osteotomy, which decreases the chance of a loss of correction during the healing process. Generally this system includes a means of engaging a fixation plate, such as fixation plate 1200 for example and a means of adjustably elastically bending or flexing the plate 1200. Once a portion of the plate in this flexed state is fixed to the bone, the bony hinge 81 may be fixed in this compressed state.
Turning now to
A method of adjustably compressing a bony hinge 81 therefore is illustrated in
The above discussion is meant to be illustrative of the principles and various embodiments of the present invention. Numerous variations and modifications will become apparent to those skilled in the art once the above disclosure is fully appreciated. It is intended that the following claims be interpreted to embrace all such variations and modifications.
Claims
1. A surgical method of attachment of a first bony segment in relation with a second bony segment, both segments belonging to a same bone, which comprises the steps of:
- cutting said bone partially, to separate it in two bony segments linked together by a bony hinge; and
- rotating both bony segments around said bony hinge, wherein the bony hinge is configured to rotate both bony segments around a single degree of freedom of the bony hinge to a final alignment that accommodates a correction in two substantially orthogonal correction planes.
2. The method of claim 1 further comprising the preoperative steps of:
- determining a relative three-dimensional positions of bony segments to obtain the final alignment of the two bony segments, the relative three-dimensional position including a rotation about the two substantially orthogonal correction planes; and
- based on the relative three dimensional positions of both bony segment, determining an orientation of the bony hinge.
3. The method of claim 1 wherein the two substantially orthogonal planes include the sagittal plane and the coronal plane.
4. The method of claim 2 wherein determining the orientation of the bony hinge, comprises using either a look-up table, computer program or mechanical computer.
5. The method of claim 2 wherein after determining the orientation of the bony hinge, drilling a hole through the bone along the determined orientation.
6. The method of claim 2 wherein determining the orientation of the bony hinge comprises determining a rotation angle of a hinge axis about a longitudinal axis of the bone and relative to a plane through the bone, the plane parallel to the either the sagittal plane or coronal plane.
7. The method of claim 2 wherein determining the orientation of the bony hinge comprises determining a rotation angle of a hinge axis about a longitudinal axis of the bone and relative to a plane through the bone and also determining a final wedge opening angle between the two boney segments.
8. The method of claim 7 wherein determining the final wedge opening angle comprises either using a look-up table, mechanical computer or a computer program.
9. The method of claim 1 further comprising fixing the first bony segment in relation with the second bony segment in the final alignment using a fixation plate, the fixation plate configured to accommodate induced loads on the bone as a result of rotating both bony segments around the single degree of freedom of the bony hinge to the final alignment that accommodates the correction in the two substantially orthogonal correction planes.
10. A surgical method of attachment of a first bony segment in relation with a second bony segment accommodating a biplanar correction, including a first and a second plane perpendicular to the first plane, and wherein both segments belong to a same bone, comprising:
- cutting partially into the bone, cutting being implemented until obtaining a partial cut which separates partially said bone in two bony segments linked together by a bony hinge, the bony hinge defining a hinge axis that is oriented at a non-zero angle relative to both the first and second plane through the bone;
- rotating said first bony segment with respect to said second bony segment around said bony hinge about a single degree of freedom until obtaining a desired three-dimensional alignment of the two bony segments, including the biplanar correction and reaching a position in which facing sides of said bony segments are separated from each other by a predetermined angle.
11. The method of claim 10 further comprising predetermining a hinge axis angle about a longitudinal axis of the bone and relative to the first plane using both a varus correction angle input and an anterior-posterior slope correction angle input and cutting partially into the bone includes drilling a hole along the predetermined hinge axis angle.
12. The method of claim 11 wherein predetermining the hinge axis angle comprises using physical charts, mechanical computer or a computer program.
13. The method of claim 11 wherein drilling the hole includes using preplanning navigation.
14. The method of claim 11 wherein drilling the hole includes using a computer piloted robot whose working head is able to be moved according to at least three degrees of freedom.
15. The method of claim 10 wherein cutting is implemented by using a computer piloted robot whose working head is configured to move according to at least three degrees of freedom, the working head supporting a cutting tool.
16. The method of claim 10 wherein cutting is implemented using a cutting guide.
17. A surgical method of attachment of a first bony segment in relation with a second bony segment, both segments belonging to a same bone, which comprises the steps of:
- determining a modified hinge axis angle of a boney hinge that provides a single degree of freedom rotation of the first bony segment relative to the second bony segment, the hinge axis angle accounting for a final desired alignment of the two bony segments including two substantially orthogonal plane corrections;
- placing an aimer assembly around the bone and orienting a guide tube of the aimer assembly in a first orientation;
- moving the guide tube along an aimer arm of the aimer assembly to orient guide tube along the modified hinge axis angle; and
- inserting a drill through the guide tube and forming a hole through the bone defining the hinge axis angle of the bony hinge.
18. The method of claim 17 wherein moving the guide tube includes sliding the guide tube along the aimer arm.
19. The method of claim 17 wherein the first orientation is defined as an orientation accounting for only one of the two substantially orthogonal plane corrections.
20. The method of claim 17 wherein the guide tube is configures to receive a hinge pin.
Type: Application
Filed: Jan 29, 2021
Publication Date: May 25, 2023
Inventors: Paul Alexander Torrie (Marblehead, MA), Dennis Colleran (North Attleboro, MA), Miles Malone (New Durham, NH), John Albert Slusarz, Jr. (Hopedale, MA), Jason Hamilton (Dartmouth, MA), Jacob Mercer (Quincy, MA), Rebecca Holmberg (Billerica, MA)
Application Number: 17/795,567